Which genotype represents a true dihybrid condition?

The Mendel dihybrid phenotypic ratio is . . . . . . .

In a plant,red fruit $(R)$ is dominant over yellow fruit $(r)$ and tallness $(T)$ is dominant over shortness $(t)$. If a plant with $RRTt$ genotype is crossed with a plant that is $rrtt$,what will be the phenotypic ratio of the offspring?

Mendel's Law of Independent Assortment is proven by .....

In plants,red fruit $(R)$ is dominant over yellow fruit $(r)$ and tall height $(T)$ is dominant over dwarf height $(t)$. If a plant with genotype $RRTt$ is crossed with a plant with genotype $RRTt$,what will be the phenotype of the offspring?

How many types of gametes may be produced by genotype $D/d : E/e : F/f$?